The Sun in extreme ultraviolet. Image Credit: Wikimedia Commons/NASA, ESA
Today’s Sunspot Number: 14
Today’s Solar Wind: speed 363.7 km/sec, density 10.6 protons/cm3,
Solar Wind current density: 3.855×108 proton/cm2/sec
Current Stretch of days without sunspots: 0
Number of Spotless Days by Year:
2017: 81 days
2016: 32 days
2015: 0 days
This page is devoted to keeping track of how active the Sun is, particularly how strong the solar wind might be. In the model of global warming we described in the Global Warming post theme, whether or not the Earth is warming depends primarily on the fraction of the Earth’s surface that is covered with clouds. The primary effect of the clouds is to shade and cool the Earth by reflecting back to space incident solar thermal radiation before it can appreciably warm the atmosphere. The fraction of cloud coverage is determined by the amount of ionizing high energy cosmic ray charged particles that penetrates the atmosphere. There it ionizes particulates that will act as cloud nucleation centers around which water droplets can condense.
Recently (news released August 25, 2016), physicists at the National Space Institute, Technical University of Denmark, and at the Racah Institute of Physics at the Hebrew University of Jerusalem published an analysis of 25 years of satellite observations strengthening the idea that there is a strong link between solar activity, cosmic ray intensity in the atmosphere, and cloud cover. I took that as an excuse to write a post summarizing the model for global warming (Not AGW!), in which I also embedded two videos of the CERN physicist Jasper Kirkby explaining his CLOUD experiment. That experiment proved that cosmic rays at typical intensities and energies in the atmosphere would ionize typical aerosol particulates with sizes and densities sufficient to serve as cloud nucleation centers. The post is Solar Wind, Cosmic Rays and Clouds: The Determinants of Global Warming.
Earth to Sky Calculus, a student group affiliated with Spaceweather.com, periodically launches weather balloons with instruments for measuring cosmic ray intensity in the stratosphere. It has just published a new graph of stratospheric cosmic ray intensity. It overlaps the old plot considerably, but adds new months into July, so I am showing both the newest plot and its predecessor below. Cosmic ray intensity is plotted in units of microsieverts per hour (uSv/hr), where a microsievert is one millionth of a Sievert, and a Sievert is a derived unit of ionizing radiation dose. Notice the data is consistent with global cooling caused by increasing cloud cover.
The amount of high energy cosmic rays that penetrate the atmosphere is determined in turn by the strength of the solar wind. It is well known that an intense solar wind can blow cosmic rays away and keep them from penetrating the inner solar system. See Clouds and Global Warming and Solar Power Output and Global Warming. For this reason it would be good to keep track of how active the Sun is to determine if we should expect the current period of global cooling to continue.
The information on this page comes primarily from the Solar Physics page of NASA’s Marshall Space Flight Center. Additional daily data is taken from spaceweather.com. As we determined in Solar Power Output and Global Warming, periods of greater solar activity with higher power output and more intense solar wind are correlated with greater numbers of sunspots on the Sun’s surface. One of the first things you will see on NASA’s Solar Physics page is the graph below.As you can see from it, we have just passed the solar maximum of the 11-year sunspot cycle and the peak sunspot number was roughly half the number in the previous solar maximum, If you were to click on this plot on the NASA page, you would get the series of plots just below our first plot.
Carefully perusing these plots, you will note in the last global warming period between 1975 and 2000, sunspot numbers at the solar maxima increased until about 1990 and then began to become smaller again. This observation would appear to agree with our model. Currently, the sunspot number is predicted to decline at least through 2020.
To determine the sun spot number, use is made of the fact that the average number of sunspots in a closely associated group of them is roughly 10. The sunspot number is then take to be approximately 10 times the number of sunspot groups plus the number of individual sunspots.
Note in the sunspot scatter plots above that from roughly 1917 to 1947(sunspot cycles 15-18) and between 1970 and 1990 (sunspot cycles 20-22), two periods of global warming in the 20th century, the peaks of the sunspot cycles were generally increasing. Also note between 1947 and 1970 (sunspot cycles18-20) and between 1990 to the present (sunspot cycles 22-24), two periods of warming hiatus or gentle cooling, the peaks of the sunspot were generally decreasing. This observation is consistent with the global warming model in the Global Warming Theme, and summarized in the post Global Warming: A Summation.
There are two “official” series of sunspot numbers: one is the International Sunspot Number maintained by the Solar Influences Data Analysis Center in Belgium; and the NOAA sunspot number compiled by the U.S. National Oceanic and Atmospheric Administration. We will report and record the NOAA data. In the tables that follow, SSN is the sunspot number, Speed is the solar wind speed in km/sec, Density is the volume density of protons in the solar wind in protons/cm3, and Current is the solar wind’s current density in protons/cm2/sec. In the first table is the monthly averaged data to the extent I have calculated it. The second table is the current daily data yet to be averaged.
Monthly Averaged Data
Daily Data Yet To Be Averaged